feat(schedule): add signSchedule tck method (hiero-ledger#2630)

Signed-off-by: Ntege Daniel <danientege785@gmail.com>
Signed-off-by: Daniel Ntege <danientege785@gmail.com>

Author: danielmarv

src/hiero_sdk_python/schedule/schedule_sign_transaction.py

@@ -61,17 +61,14 @@ def _build_proto_body(self):
         """
         Returns the protobuf body for the schedule sign transaction.
 
+        An unset schedule ID is omitted from the body rather than rejected locally, so the
+        network answers with INVALID_SCHEDULE_ID as it does for the other SDKs.
+
         Returns:
             ScheduleSignTransactionBody: The protobuf body for this transaction.
-
-        Raises:
-            ValueError: If schedule_id is not set.
         """
-        if self.schedule_id is None:
-            raise ValueError("Missing required ScheduleID")
-
         return ScheduleSignTransactionBody(
-            scheduleID=self.schedule_id._to_proto(),
+            scheduleID=self.schedule_id._to_proto() if self.schedule_id is not None else None,
         )
 
     def build_transaction_body(self):

tck/handlers/schedule.py

@@ -8,6 +8,7 @@
 from hiero_sdk_python.schedule.schedule_create_transaction import ScheduleCreateTransaction
 from hiero_sdk_python.schedule.schedule_delete_transaction import ScheduleDeleteTransaction
 from hiero_sdk_python.schedule.schedule_id import ScheduleId
+from hiero_sdk_python.schedule.schedule_sign_transaction import ScheduleSignTransaction
 from hiero_sdk_python.timestamp import Timestamp
 from hiero_sdk_python.transaction.transaction import Transaction
 from hiero_sdk_python.transaction.transaction_receipt import TransactionReceipt
@@ -22,11 +23,16 @@
 from tck.param.allowance import ApproveAllowanceParams
 from tck.param.base import BaseTransactionParams
 from tck.param.common import CommonTransactionParams
-from tck.param.schedule import CreateScheduleParams, DeleteScheduleParams, ScheduledTransactionParams
+from tck.param.schedule import (
+    CreateScheduleParams,
+    DeleteScheduleParams,
+    ScheduledTransactionParams,
+    SignScheduleParams,
+)
 from tck.param.token import BurnTokenParams, MintTokenParams
 from tck.param.topic import CreateTopicParams, TopicMessageSubmitParams
 from tck.param.transfer import TransferCryptoParams
-from tck.response.schedule import CreateScheduleResponse, DeleteScheduleResponse
+from tck.response.schedule import CreateScheduleResponse, DeleteScheduleResponse, SignScheduleResponse
 from tck.util.client_utils import get_client
 from tck.util.constants import DEFAULT_GRPC_TIMEOUT
 from tck.util.key_utils import get_key_from_string
@@ -118,6 +124,16 @@ def _build_create_schedule_transaction(params: CreateScheduleParams) -> Schedule
     return transaction
 
 
+def _build_sign_schedule_transaction(params: SignScheduleParams) -> ScheduleSignTransaction:
+    """Build a ScheduleSignTransaction from TCK params."""
+    transaction = ScheduleSignTransaction().set_grpc_deadline(DEFAULT_GRPC_TIMEOUT)
+
+    if params.scheduleId is not None:
+        transaction.set_schedule_id(ScheduleId.from_string(params.scheduleId))
+
+    return transaction
+
+
 def _build_delete_schedule_transaction(params: DeleteScheduleParams) -> ScheduleDeleteTransaction:
     """Builds a ScheduleDeleteTransaction from the provided parameters."""
     transaction = ScheduleDeleteTransaction().set_grpc_deadline(DEFAULT_GRPC_TIMEOUT)
@@ -152,6 +168,32 @@ def create_schedule(params: CreateScheduleParams) -> CreateScheduleResponse:
     return CreateScheduleResponse(schedule_id, scheduled_transaction_id, ResponseCode(receipt.status).name)
 
 
+@rpc_method("signSchedule")
+def sign_schedule(params: SignScheduleParams) -> SignScheduleResponse:
+    """Sign a schedule."""
+    common_params = params.commonTransactionParams
+    if (
+        common_params is not None
+        and common_params.maxTransactionFee is not None
+        and common_params.maxTransactionFee < 0
+    ):
+        # Protobuf transactionFee is unsigned, so a negative TCK boundary value
+        # cannot reach network precheck in this SDK.
+        raise JsonRpcError.hiero_error({"status": ResponseCode.INSUFFICIENT_TX_FEE.name})
+
+    client = get_client(params.sessionId)
+
+    transaction = _build_sign_schedule_transaction(params)
+
+    if common_params is not None:
+        common_params.apply_common_params(transaction, client)
+
+    response = transaction.execute(client, wait_for_receipt=False)
+    receipt: TransactionReceipt = response.get_receipt(client, validate_status=True)
+
+    return SignScheduleResponse(status=ResponseCode(receipt.status).name)
+
+
 @rpc_method("deleteSchedule")
 def delete_schedule(params: DeleteScheduleParams) -> DeleteScheduleResponse:
     """Handles the deleteSchedule JSON-RPC request."""

tck/param/schedule.py

@@ -64,6 +64,22 @@ def parse_json_params(cls, params: dict) -> CreateScheduleParams:
         )
 
 
+@dataclass
+class SignScheduleParams(BaseTransactionParams):
+    """Request parameters for the signSchedule endpoint."""
+
+    scheduleId: str | None = None
+
+    @classmethod
+    def parse_json_params(cls, params: dict) -> SignScheduleParams:
+        """Parse JSON-RPC params into a SignScheduleParams instance."""
+        return cls(
+            scheduleId=params.get("scheduleId"),
+            sessionId=parse_session_id(params),
+            commonTransactionParams=parse_common_transaction_params(params),
+        )
+
+
 @dataclass
 class DeleteScheduleParams(BaseTransactionParams):
     """Parse JSON-RPC params into a DeleteScheduleParams instance."""

tck/response/schedule.py

@@ -14,6 +14,11 @@ class CreateScheduleResponse:
     status: str | None = None
 
 
+@dataclass
+class SignScheduleResponse(StatusOnlyResponse):
+    """Response payload for signSchedule."""
+
+
 @dataclass
 class DeleteScheduleResponse(StatusOnlyResponse):
     """Response payload for deleteSchedule."""

tests/integration/schedule_sign_transaction_e2e_test.py

@@ -6,6 +6,7 @@
 
 import pytest
 
+from hiero_sdk_python.exceptions import PrecheckError
 from hiero_sdk_python.response_code import ResponseCode
 from hiero_sdk_python.schedule.schedule_id import ScheduleId
 from hiero_sdk_python.schedule.schedule_info_query import ScheduleInfoQuery
@@ -187,6 +188,17 @@ def test_integration_schedule_sign_transaction_fails_invalid_schedule_id(env):
     )
 
 
+@pytest.mark.integration
+def test_integration_schedule_sign_transaction_fails_without_schedule_id(env):
+    """Test that ScheduleSignTransaction fails precheck when no schedule ID is set.
+
+    The body omits scheduleID entirely, which the network rejects in pureChecks, so the
+    failure arrives as a precheck error rather than a receipt status.
+    """
+    with pytest.raises(PrecheckError, match="failed precheck with status: INVALID_SCHEDULE_ID"):
+        ScheduleSignTransaction().freeze_with(env.client).sign(env.operator_key).execute(env.client)
+
+
 def test_integration_schedule_sign_transaction_fails_with_already_executed(env):
     """Test that ScheduleSignTransaction fails when the schedule has already been executed."""
     account = env.create_account()

tests/unit/schedule_sign_transaction_test.py

@@ -76,12 +76,17 @@ def test_build_proto_body_with_schedule_id(schedule_id):
     assert proto_body.scheduleID == schedule_id._to_proto()
 
 
-def test_build_proto_body_without_schedule_id_raises_error():
-    """Test building protobuf body without a schedule ID."""
+def test_build_proto_body_without_schedule_id_omits_field():
+    """Test that building a protobuf body without a schedule ID leaves the field unset.
+
+    The network rejects a body with no scheduleID with INVALID_SCHEDULE_ID, so the
+    omission is left for it to answer instead of failing locally.
+    """
     schedule_sign_tx = ScheduleSignTransaction()
 
-    with pytest.raises(ValueError, match="Missing required ScheduleID"):
-        schedule_sign_tx._build_proto_body()
+    proto_body = schedule_sign_tx._build_proto_body()
+
+    assert not proto_body.HasField("scheduleID")
 
 
 def test_build_transaction_body_with_valid_schedule_id(mock_account_ids, schedule_id):